PDL::PP-Inline - Man Page

Write PDL Subroutines inline with PDL::PP


Inline::Pdlpp is a module that allows you to write PDL subroutines in the PDL::PP style. The big benefit compared to plain PDL::PP is that you can write these definitions inline in any old perl script (without the normal hassle of creating Makefiles, building, etc). Since version 0.30 the Inline module supports multiple programming languages and each language has its own support module. This document describes how to use Inline with PDL::PP (or rather, it will once these docs are complete ;).

For more information on Inline in general, see Inline.

Some example scripts demonstrating Inline::Pdlpp usage can be found in the Example/InlinePdlpp directory.

Inline::Pdlpp is a subclass of Inline::C. Most Kudos goes to Brian I.


You never actually use Inline::Pdlpp directly. It is just a support module for using Inline.pm with PDL::PP. So the usage is always:

    use Inline Pdlpp => ...;


    bind Inline Pdlpp => ...;


Pending availability of full docs a few quick examples that illustrate typical usage.

A simple example

   # example script inlpp.pl
   use PDL; # must be called before (!) 'use Inline Pdlpp' calls

   use Inline Pdlpp; # the actual code is in the __Pdlpp__ block below

   $x = sequence 10;
   print $x->inc,"\n";
   print $x->inc->dummy(1,10)->tcumul,"\n";



          Pars => 'i();[o] o()',
          Code => '$o() = $i() + 1;',

          Pars => 'in(n);[o] mul()',
          Code => '$mul() = 1;
                   loop(n) %{
                     $mul() *= $in();
   # end example script

If you call this script it should generate output similar to this:

   prompt> perl inlpp.pl
   Inline running PDL::PP version 2.2...
   [1 2 3 4 5 6 7 8 9 10]
   [3628800 3628800 3628800 3628800 3628800 3628800 3628800 3628800 3628800 3628800]

Usage of Inline::Pdlpp in general is similar to Inline::C. In the absence of full docs for Inline::Pdlpp you might want to compare Inline::C.

Code that uses external libraries, etc

The script below is somewhat more complicated in that it uses code from an external library (here from Numerical Recipes). All the relevant information regarding include files, libraries and boot code is specified in a config call to Inline. For more experienced Perl hackers it might be helpful to know that the format is similar to that used with ExtUtils::MakeMaker. The keywords are largely equivalent to those used with Inline::C. Please see below for further details on the usage of Inc, Libs, Auto_include and Boot.

   use PDL; # this must be called before (!) 'use Inline Pdlpp' calls

   use Inline Pdlpp => Config =>
     INC => "-I$ENV{HOME}/include",
     LIBS => "-L$ENV{HOME}/lib -lnr -lm",
     # code to be included in the generated XS
   #include <math.h>
   #include "nr.h"    /* for poidev */
   #include "nrutil.h"  /* for err_handler */

   static void nr_barf(char *err_txt)
     fprintf(stderr,"Now calling croak...\n");
     croak("NR runtime error: %s",err_txt);
   # install our error handler when loading the Inline::Pdlpp code
   BOOT => 'set_nr_err_handler(nr_barf);';

   use Inline Pdlpp; # the actual code is in the __Pdlpp__ block below

   $x = zeroes(10) + 30;;
   print $x->poidev(5),"\n";



           Pars => 'xm(); [o] pd()',
           GenericTypes => [L,F,D],
           OtherPars => 'long idum',
           Code => '$pd() = poidev((float) $xm(), &$COMP(idum));',

Pdlpp Configuration Options

For information on how to specify Inline configuration options, see Inline. This section describes each of the configuration options available for Pdlpp. Most of the options correspond either to MakeMaker or XS options of the same name. See ExtUtils::MakeMaker and perlxs.


Specifies extra statements to automatically included. They will be added onto the defaults. A newline char will be automatically added. Does essentially the same as a call to pp_addhdr. For short bits of code AUTO_INCLUDE is probably syntactically nicer.

    use Inline Pdlpp => Config => AUTO_INCLUDE => '#include "yourheader.h"';


Same as pp_bless command. Specifies the package (i.e. class) to which your new pp_defed methods will be added. Defaults to PDL if omitted.

    use Inline Pdlpp => Config => BLESS => 'PDL::MyPackage';

cf "Package", equivalent for "pp_addxs" in PDL::PP.


Specifies C code to be executed in the XS BOOT section. Corresponds to the XS parameter. Does the same as the pp_add_boot command. Often used to execute code only once at load time of the module, e.g. a library initialization call.


Specify which compiler to use.


Specify extra compiler flags.


Specifies an include path to use. Corresponds to the MakeMaker parameter.

    use Inline Pdlpp => Config => INC => '-I/inc/path';


Specify which linker to use.


Specify which linker flags to use.

NOTE: These flags will completely override the existing flags, instead of just adding to them. So if you need to use those too, you must respecify them here.


Specifies external libraries that should be linked into your code. Corresponds to the MakeMaker parameter.

    use Inline Pdlpp => Config => LIBS => '-lyourlib';


    use Inline Pdlpp => Config => LIBS => '-L/your/path -lyourlib';


Specify the name of the 'make' utility to use.


Specifies a user compiled object that should be linked in. Corresponds to the MakeMaker parameter.

    use Inline Pdlpp => Config => MYEXTLIB => '/your/path/yourmodule.so';


This controls the MakeMaker OPTIMIZE setting. By setting this value to '-g', you can turn on debugging support for your Inline extensions. This will allow you to be able to set breakpoints in your C code using a debugger like gdb.


Controls into which package the created XSUBs from "pp_addxs" in PDL::PP go. E.g.:

    use Inline Pdlpp => 'DATA', => PACKAGE => 'Other::Place';

will put the created routines into Other::Place, not the calling package (which is the default). Note this differs from "Bless", which is where "pp_def" in PDL::PPs go.


Specifies extra typemap files to use. Corresponds to the MakeMaker parameter.

    use Inline Pdlpp => Config => TYPEMAPS => '/your/path/typemap';


Show the output of any compilations going on behind the scenes. Turns on BUILD_NOISY in Inline::C.


doing inline scripts

Beware that there is a problem when you use the __DATA__ keyword style of Inline definition and want to do your script containing inlined code. For example

   # myscript.pl contains inlined code
   # in the __DATA__ section
   perl -e 'do "myscript.pl";'
 One or more DATA sections were not processed by Inline.

According to Brian Ingerson (of Inline fame) the workaround is to include an Inline->init call in your script, e.g.

  use PDL;
  use Inline Pdlpp;

  # perl code


  # pp code

PDL::NiceSlice and Inline::Pdlpp

There is currently an undesired interaction between PDL::NiceSlice and Inline::Pdlpp. Since PP code generally contains expressions of the type $var() (to access ndarrays, etc) PDL::NiceSlice recognizes those incorrectly as slice expressions and does its substitutions. For the moment (until hopefully the parser can deal with that) it is best to explicitly switch PDL::NiceSlice off before the section of inlined Pdlpp code. For example:

  use PDL::NiceSlice;
  use Inline::Pdlpp;

  $x = sequence 10;

  no PDL::NiceSlice;



  ppdef (...); # your full pp definition here


Brian Ingerson for creating the Inline infrastructure.


Christian Soeller <soellermail@excite.com>

See Also






2024-04-07 perl v5.38.2 User Contributed Perl Documentation